4G VoLTE calls confirmed working with carrier x

[dukla2000]

Three UK on a Three UK SIM, VoLTE working both outgoing and incoming, display icon stayed 4G during both calls.

Outgoing call:

Code:

$ sudo mmcli -m any --command='AT+CLCC'
response: '+CLCC: 1,1,0,1,0,"",128
+CLCC: 2,1,0,1,0,"",128
+CLCC: 3,0,0,0,0,"+44118973xxxx",145
+CLCC: 4,1,0,1,0,"",128'

Incoming call:

Code:

$ sudo mmcli -m any --command='AT+CLCC'
[sudo] password for alarm:
response: '+CLCC: 1,1,0,1,0,"",128
+CLCC: 2,1,0,1,0,"",128
+CLCC: 4,1,0,0,0,"0794186xxxx",128
+CLCC: 3,1,0,1,0,"",128'

{The xxxx in the MSISDN are manually altered.}

Completely standard (but up to date) Arch image

Code:

$ uname -a
Linux dukla 5.10.0-1-danctnix #1 SMP Tue Dec 15 09:44:29 +07 2020 aarch64 GNU/Linux

ps - I have no idea which profile is being used as there isn't 1 for 3 UK - presumably some default worked fine because I hae done nothing explicit!